Even Slightly-Elevated Blood Pressure Can Spell Trouble

Nov. 16, 2001 -- With new evidence that even slightly-elevated blood pressure can easily become dangerous high blood pressure (hypertension) as we age or gain weight, British experts are now recommending vigilant monitoring even for those with "high-normal" and normal pressure.

High blood pressure is a direct cause of heart attack, stroke, and heart failure. Just recently, WebMD reported on a large study showing that people whose blood pressure falls on the high end of the "normal" spectrum are twice as likely to suffer one of these potentially catastrophic events than are those with pressure in the lower ranges of normal.

Now, another data analysis from that same Framingham Heart Study of more than 10,000 healthy men and women with "normal" blood pressure shows that even these people can quickly develop full-blown hypertension. Any blood pressure reading of less than 140/90 mm Hg ("one-forty over ninety") is considered normal, but pressures of less than 120/80 mm Hg ("one-twenty over eighty") are considered ideal.

The researchers divided everyone into two age groups -- under 65, and 65 and over, and into three blood-pressure groups -- those in the lowest, the middle, and the highest ranges of normal.

Their latest findings appear in the Nov. 17 issue of The Lancet medical journal.

During the four-year study period, only 5% of those under age 65 who'd started out in the optimum range of "normal" developed hypertension, compared with 37% of those in the high-normal range. And among those over age 65, half in the high-normal range, a quarter in the mid-range, and 16% in the optimum range, developed high blood pressure.

Growing older put everyone at increased risk of high blood pressure and emphasizes the need to maintain a healthy lifestyle -- eating right, exercising, not smoking -- as we age. But what is especially important considering our country's obesity epidemic is that people who gained weight -- even just a 5% increase -- were 20% to 30% more likely to see their blood pressure shoot up.

"High normal blood pressure and normal blood pressure frequently progress to hypertension ... especially in older adults," the researchers write. "These findings support recommendations for monitoring individuals with high normal blood pressure once a year, and monitoring those with normal blood pressure every two years, and they emphasize the importance of weight control as a measure for [preventing] hypertension."